1. Field of the Invention
The present invention relates to a projection display system having a light source and a projection device mounted thereon.
2. Description of the Related Art
Conventionally, there are projection display systems that form an optical image according to an image signal using a display device based on light from a light source, and enlargedly projects the formed optical image on a screen through a projection lens, to obtain a large-screen image. The conventional projection display system includes a white light source such as a mercury lamp as a light source, in which a color-separating optical filter separates light into a plurality of monochromatic light components such as red, green, and blue, thereby realizing videos in full colors. Some of recent systems use a laser such as a semiconductor laser as a light source, instead of the while light source, on which a plurality of monochromatic lasers are mounted, thereby realizing images in full colors.
When laser light is used as the light source, it is necessary to prevent leakage of scattered light generated on surfaces of a mirror, a lens, and the like to ensure security of human bodies or objects. Prevention of light leakage is also useful in efficiently using light. Areas where light leakage occurs include a gap generated at a joint between components constituting an enclosure of a light source device or a projection device. A conventional technique related to countermeasures against light leakage from a gap is disclosed in Japanese Patent Application Laid-open No. 2005-098001.
However, application of the technique disclosed in Japanese Patent Application Laid-open No. 2005-098001 is limited to sliding doors. Furthermore, this technique is aimed not at laser light but at illumination light, and accordingly light shielding is not so strict. Therefore, the technique disclosed in Japanese Patent Application Laid-open No. 2005-098001 cannot prevent leakage of light from the gap generated at the joint between the components constituting the enclosure of the light source device or the projection device.